Thanks: Eric Blake.
---
include/nbdkit-common.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/include/nbdkit-common.h b/include/nbdkit-common.h
index f8517d5..3177878 100644
--- a/include/nbdkit-common.h
+++ b/include/nbdkit-common.h
@@ -34,6 +34,10 @@
#ifndef NBDKIT_COMMON_H
#define NBDKIT_COMMON_H
+#if !defined (NBDKIT_PLUGIN_H) && !defined (NBDKIT_FILTER_H)
+#error this header file should not be directly included
+#endif
+
#include <stdarg.h>
#include <stdint.h>
--
2.15.1